<!DOCTYPE html>
<html lang="en">

<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
</head>

<body>
    <script>
        var arr = [{ name: 'zhangsan', age: 10 }, { name: 'lisi', age: 18 }]
        arr[0].age = 19;

        console.log(arr[0]);// age 19


        var obj2 = { age: 999 };
        var arr2 = [obj2];
        obj2.age = 888;

        console.log(arr2[0].age);//888
    </script>
</body>

</html>